The impact of the COVID-19 pandemic on sleep disorders among Nursing professionals

Abstract Objective: to analyze the factors related to sleep disorders reported by Nursing professionals during the COVID-19 pandemic. Method: this is a cross-sectional and analytical study conducted with Nursing professionals from all Brazilian regions. Sociodemographic data, working conditions and questions about sleep disorders were collected. The Poisson regression model with repeated measures was used to estimate the Relative Risk. Results: 572 answers were analyzed, which revealed that non-ideal sleep duration, poor sleep quality and dreams about the work environment were predominant during the pandemic, with 75.2%, 67.1% and 66.8% respectively; as well as complaints of difficulty sleeping, daytime sleepiness and non-restorative sleep during the pandemic were reported by 523 (91.4%), 440 (76.9%) and 419 (73.2%) of the Nursing professionals, respectively. The relative risk of having such sleep disorders during the pandemic was significant for all variables and categories studied. Conclusion: non-ideal sleep duration, poor sleep quality, dreams about the work environment, complaints regarding difficulty sleeping, daytime sleepiness and non-restorative sleep were the predominant sleep disorders among Nursing professionals during the pandemic. Such findings point to possible consequences on health, as well as on the quality of the work performed.


Introduction
Coping with COVID-19, a disease caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), can lead to the emergence of physical and emotional problems such as anxiety, fear, depressive symptoms and changes in the circadian cycle, with disturbances in the sleep pattern (1) .
Sleep quality is intrinsically related to neurobehavioral functions and to balance of the immune system, being considered one of the mechanisms to reduce contamination by opportunistic diseases (2)(3) .
In health professionals, the impacts of the pandemic are enhanced by physical exhaustion, high workload, lack of personal protective equipment, inadequate working conditions, need for ethically complex decisions on care rationing, emotional tensions and severity of the cases (4) .
Such occupational demands are frequent causes of stress and insufficient sleep and can contribute to changes in the work process, increasing the risk of accidents (5) .
High stress levels and poor sleep quality are among the effects observed in Nursing professionals (5) . In a study conducted with 2,372 nurses, it was observed that 69.3% presented habitual sleep deficits and that the lower the mindfulness level and the worse the work/ family conflict, the worse the sleep quality (6) . Thus, the improvement in sleep satisfaction, duration and efficiency can promote benefits for well-being and for the quality of Nursing care (7) .
The recommendations for adequate sleep-related quality and duration are important tools for the public health context. Due to the importance of sleep in several health and well-being aspects, the National Sleep Foundation (2020) (8) published the importance of sleep and guidelines for sleeping well during the COVID-19 pandemic.
A number of experts warn that, during the pandemic, people started to have more dreams and remember them more easily, in addition to reporting that they often involved images and unpleasant situations. More disturbed sleep can increase the probability of worrisome dreams, in turn causing stress and anxiety, which impair sleep quality (8) . Given this context, this research was guided by the hypothesis that the COVID-19 pandemic may have negatively affected the sleep of Nursing professionals working in health care.
Considering the importance of sleep throughout the life and work dynamics, this study aims at analyzing the factors related to sleep disorders reported by Nursing professionals during the COVID-19 pandemic.

Type of study
This is a cross-sectional and analytical study, based on Strengthening the Reporting of Observational studies in Epidemiology (STROBE) (9) .

Locus
It was conducted in all Brazilian regions.

Period
June and July 2020.

Population
Nursing professionals who worked in health care.

Selection criteria
The inclusion criteria adopted were the following: age greater than or equal to 18 years old and whether the Nursing professional was working in health care during the COVID-19 pandemic. Workers exclusively working in the night shift were excluded.

Definition of the sample
Sample calculation was performed in order to estimate the proportion of participants with sleep disorders. For this purpose, the reference was the population of Nursing professionals in the country: 2,304,509 (10) , with 5% sampling error and 99% confidence level. A proportion of 0.5 was considered, whose value represents the maximum variability of the binomial distribution, which generated an estimate with the largest possible sample size (11) . For this study, the estimated sample size was 664 participants.

Study variables
The variables of interest in the study were as follows: identification of the Nursing professional, gender (men, women), professional training (nursing assistant, nursing technician, nurse), number of work contracts (one, two or more), weekly hour load (20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) hours, 31-40 hours, 41-50 hours, more than 50 hours) and health performance levels (primary and secondary, tertiary, pre-hospital). Also in relation to sleep, some variables were built by asking the following questions before the pandemic: "How many hours of sleep did you use to sleep per night", "Which difficulties did you experience when sleeping?", "Did you feel sleepy during the day?", "Did you use to have dreams about the work environment?", "Did you wake up willing after sleep?", "How did you classify your sleep?" and the below www.eerp.usp.br/rlae 3 Andrechuk CRS, Caliari JS, Santos MA, Pereira FH, Oliveira HC, Ceolim MF. questions during the pandemic: "How many hours of sleep do you sleep per night?", "Which difficulties do you experience when sleeping?", "Do you feel sleepy during the day?", "Do you usually have dreams about the work environment?", "Do you wake up willing after sleep?", "How do you classify your sleep?" and "Have you started using sleep medications?". According to the answers, the following categories were considered for analysis: ideal sleep duration (7-8 hours) and non-ideal sleep duration (less than or equal to 6 hours or greater than or equal to 09 hours) (12) ; poor sleep quality (poor and very poor answers) and good sleep quality (very good and good answers); there were two possible answers for all the other variables: Yes or No.

Data collection
The study was conducted through an online questionnaire, self-completed through a computer or mobile phone with Internet access. The questionnaire was prepared using the Google Forms app. The "snowball" chain sampling procedure adapted to virtual social networks was used (13) . At the beginning of the study, invitations were sent with the link to access the questionnaire through the Facebook and Instagram virtual social networks, WhatsApp or e-mail to an initial group of people who are part of the target population (called "seeds"), which indicate peers from the same population group and so on.  (14) and simple measures, as well as for those with an interaction effect, with presentation of their respective 95% confidence intervals and p-values with the significance level set at 5% (p<0.05).

Ethical aspects
The study was submitted and approved by

Results
A total of 577 answers to the survey were received; however, 572 Nursing professionals who met the inclusion criteria were considered to comprise the sample. Description  Table 1.

Discussion
Working in health care during the COVID-19 pandemic caused several physical and psychological disorders in many professionals, especially nursing assistants, nursing technicians and nurses.
The results described confirm the impact of the pandemic on sleep disorders and corroborate other studies that point to variables such as gender (15)(16) , professional training (4) , number of work contracts, weekly hour load (1,(16)(17) and having started using sleep medications (4) , related to sleep disorders.
Harmful outcomes in the sleep quality of the Nursing professionals (4) who work directly with people affected by COVID-19 have been reported, which can be related to increased stress in the work environments and to the impact on the habitual sleep patterns (5,17) .
The risk for sleep disorders during the pandemic was significant for both genders in all variables, except in relation to the dreams about the work environment, where only the women remained statistically significant.
In the relationship between the gender variable and sleep disorders, being a woman has always been associated with greater chances of having sleep disorders when compared to men, which corroborates a national study carried out with 45,160 individuals aged 18 years old and over, in which 51.1% of the participants were women and presented an increase or incidence of sleep problems during the pandemic, when compared to the men (37.7%) with the same problems (16) .
Being a woman increased the chance for deterioration in terms of sleep problems during the pandemic. They tended to present worse health conditions and higher work overload due to double or triple workdays, which can be more incident during this period, especially in relation to household chores (16,18) .
In an Italian study conducted with Nursing professionals who treated COVID-19 patients, it was identified that being a woman was associated with higher anxiety and sleep deprivation levels and that gender was a predictive factor for increased anxiety and poor sleep quality (19) .
During the pandemic, nursing technicians and nurses presented a significant risk of developing all the  (20) .
In a cross-sectional study conducted with 1,257 health professionals in 34 hospitals from China, the Nursing professionals reported more severe degrees of all the measurements of depression, anxiety, insomnia and distress symptoms than other health professionals, pointing out that the professionals working on the front line were at a high risk of developing changes in their health, requiring immediate care (18) .
In relation to the number of work contracts, although the association was statistically significant for the "one" and "two or more" categories, it was noticed that having "two or more contracts" was related to a higher chance of presenting sleep disorders, which can be explained by the increased workload and the fear of infecting people at their homes.
During the COVID-19 pandemic, in addition to working long hours with a high risk of infection, Nursing professionals sometimes also faced situations of lack of medical supplies and personnel, due to illness in their colleagues, which contributes to anxiety and stress (6) , thus affecting sleep quality.
In a study carried out in Turkey, 81.4% of the nurses reported that their co-workers were infected by COVID-19 and 92.6% stated they were afraid of infecting people in their homes and such results are linked to increased stress scores and related to poor sleep patterns (5) . Likewise, despite being statistically significant in all categories, the relationship with the weekly hour load corroborates that the predominance of 50 hours or more, with a higher chance of presenting sleep disorders, points to the impact of work activities in the sleep profile, which can be linked to increased stress, suggesting that sleep problems are common in health professionals who experience high stress levels at work (5) .
In a study carried out by the Oswaldo Cruz  (1,16) .
With the pandemic and the increase in work overload, tension in the work environment increased and the hours of sleep decreased. In a national study conducted with the general population, the results showed that 67% of the people had a change in their sleep routine, with some individuals sleeping more hours a day and others less (21) . In another study conducted in the Philippines with clinical nurses, it was found that low scores on the pandemic fatigue scale were related to better sleep quality and to greater job satisfaction. It is essential that institutional measures are in place to address this issue in the professionals and to promote their health and overall well-being (22) .  (1,23) .
It is known that sleep disorders can be the result of malfunctions in various regulatory mechanisms.
Insomnia, for example, is a multidimensional condition that reflects the changes in physical, mental and emotional aspects, representing a difficulty initiating, maintaining and consolidating sleep or deterioration in the overall sleep quality, generating or aggravating the physical and mental harms (24) . In addition, low quality in the sleep pattern might also contribute to accidents and risky behaviors, causing failures in the care provided, as well as harms to the patient and the institution (25) . Thus, the

Conclusion
The results clearly point out that, during the pandemic, The data showed the urgent need for interventions that can minimize the risks caused by COVID-19, especially in the sleep of the professionals who work on the front line in the fight against this disease, which is a concern to maintain the quality of the Nursing care offered.